1. Field
Example embodiments relate to a power device, and more particularly, to a power device chip including a plurality of unit devices divided into sectors and/or a method of manufacturing the power device chip.
2. Description of the Related Art
The chip size of a power device may be proportional to a current flowing in the power device. When a power device is designed for a large current, the chip size of the power device may be increased to handle the large current. For example, a chip having a size of 100 mm2 may be used to obtain a power device in which a current of 100 A or more flows. When a current is less than 100 A, the chip size of a power device may be smaller than 100 mm2.
Wafers used to manufacture semiconductor devices, such as power devices, may have defects for several reasons. Therefore, as the wafer defects decrease, the yield of the semiconductor device may increase.
However, it is practically and technically difficult to completely remove wafer defects. If the wafer defects are managed to an appropriate level, the yield of a semiconductor device using the wafer may increase with a decrease in the chip size of the semiconductor device.
Such a fact may also be applied to power devices. However, since power devices are used in high-voltage and/or large-current environments as described above, it may be difficult to reduce their chip sizes, unlike general semiconductor memory devices.
If a power device is manufactured using an 8-inch wafer and the chip size of the power device is 100 mm2, it is known that, when the wafer has no more than 100 defects, a yield of about 73% may be secured.
To improve the yield of power devices, at present, a source finger, a drain finger, and a gate finger of a broken-down part of a chip may be cut out, and the other parts may be used. In this yield-improvement, a process of searching for the broken-down part is preceded. However, it is not easy to find the broken-down part. In addition, since a thick metal and a thick dielectric may be used to deal with a large current, cutting the thick metal and the thick dielectric may be difficult. Therefore, it may be difficult to uniformly cut broken-down parts out of a chip; consequently, the remaining part may be vulnerable to a high voltage.